package com.jied.duodian.util;

import com.jied.duodian.entity.Dutity.DdOUser;
import io.jsonwebtoken.Claims;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;
import lombok.Data;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.stereotype.Component;

import java.util.Date;
import java.util.HashMap;
import java.util.Map;

/**
 * Description:
 *
 * @author LiJie
 * @date Created on 2020/10/30
 * WWW https://github.com/j6l
 */
@Data
@Component
@Slf4j
public class JwtTokenUtil {

    private String secret = "2016010261sss";

    // 过期时间 毫秒
    private Long expiration = 1000l * 60 * 60 * 3;

    @Value("${jwt.header}")
    private String header;

    @Value("${jwt.tokenHead}")
    private String tokenHead;


    /**
     * 从数据声明生成令牌
     *
     * @param claims 数据声明
     * @return 令牌
     */
    private String generateToken(Map<String, Object> claims) {
        Date expirationDate = new Date( System.currentTimeMillis() + expiration );
        return Jwts.builder().setClaims( claims ).setExpiration( expirationDate ).signWith( SignatureAlgorithm.HS512, secret ).compact();
    }

    /**
     * 从令牌中获取数据声明
     *
     * @param token 令牌
     * @return 数据声明
     */
    private Claims getClaimsFromToken(String token) {
        Claims claims;
        try {
            claims = Jwts.parser().setSigningKey( secret ).parseClaimsJws( token ).getBody();
        } catch (Exception e) {
            claims = null;
        }
        return claims;
    }

    /**
     * 生成令牌
     *
     * @param userDetails 用户
     * @return 令牌
     */
    public String generateToken(UserDetails userDetails) {
        Map<String, Object> claims = new HashMap<>( 2 );
        claims.put( Claims.SUBJECT, userDetails.getUsername() );
        claims.put( Claims.ISSUED_AT, new Date() );
        return generateToken( claims );
    }

    /**
     * 从令牌中获取用户名
     *
     * @param token 令牌
     * @return 用户名
     */
    public String getUsernameFromToken(String token) {
        String username;
        try {
            Claims claims = getClaimsFromToken( token );
            username = claims.getSubject();
        } catch (Exception e) {
            username = null;
        }
        return username;
    }

    /**
     * 判断令牌是否过期
     *
     * @param token 令牌
     * @return 是否过期
     */
    public Boolean isTokenExpired(String token) {
        try {
            Claims claims = getClaimsFromToken( token );
            Date expiration = claims.getExpiration();
            return expiration.before( new Date() );
        } catch (Exception e) {
            return true;
        }
    }

    /**
     * 刷新令牌
     *
     * @param token 原令牌
     * @return 新令牌
     */
    public String refreshToken(String token) {
        String refreshedToken;
        try {
            Claims claims = getClaimsFromToken( token );
            claims.put( Claims.ISSUED_AT, new Date() );
            refreshedToken = generateToken( claims );
        } catch (Exception e) {
            refreshedToken = null;
        }
        return refreshedToken;
    }

    /**
     * 验证令牌
     *
     * @param token       令牌
     * @param userDetails 用户
     * @return 是否有效
     */
    public Boolean validateToken(String token, UserDetails userDetails) {
        DdOUser user = (DdOUser) userDetails;
        String username = getUsernameFromToken( token );
        log.info( "用户  {}   效验 {}", userDetails.getUsername(), token );
        return (username.equals( user.getUsername() ) && !isTokenExpired( token ));
    }
}
